1. Field of the Invention
The present invention relates to an automatic handling and sequencing system for controlling the playback of tape cassettes, and more particularly videotape cassettes. In television broadcasting, a number of short video messages, or "spots", are often shown in sequence, e.g., during commercial breaks. Multiple videotape playback machines are employed to play these spots. After each spot, a machine must be loaded with a new cassette for playback later during the same break or in a subsequent break. The loading and unloading of the tape playback machines thus requires almost constant attention.
2. Description of the Prior Art
Automated video spot players have been previously developed. Such players include a plurality of videotape playback machines and some form of tape cartridge or cassette conveyor mechanism for transporting cartridges or cassettes containing video tape to and from the playback machines. In some machines, a number of tape cartridges (generally between fifteen and twenty-five) are carried on a moving carousel which brings the cartridges into position adjacent the desired tape playback unit. Although these systems provide some automation to spot broadcasting, they have the drawback of requiring a custom cartridge for the videotape. In addition, the conveyor system of such systems is relatively complex and expensive to build and maintain.
A more recently developed system incorporates a column of storage bins for standard videocassettes and an elevator mechanism which is employed to access the videocassettes and load transport units which are part of the system. In this system, forty videocassettes are carried in a single column of storage bins. After a cassette is placed in a bin by the operator of the machine, a bar code label on the cassette is read by a bar code reader in order to enable a computer control system to determine the location of the cassette and control the subsequent transport of cassettes to the tape transports. Although this system provides several improvements over previous sequencing systems, it still has several important limitations. Primary among these is the limited capacity of the system. Since only forty cassettes can be placed in the system, a great deal operator attention is still required. A further disadvantage is that the storage bins include mechanisms for aiding in the removal of tapes and preventing the inadvertant operator insertion of tapes into bins from which a cassette has been removed for playback, thereby resulting in a relatively complex machine.